Foam mixing head

ABSTRACT

Two foamable chemicals are diverted from a recirculation path by simultaneously operable pivoting ball valves to respective separate paths through respective one way valves, pressure responsive normally closed poppet valves, and a common conduit to a common mixing chamber wherein they are mixed by identical counter rotating shafts having roll pins extending through diametric bores, before the thus mixed chemicals are discharged into a suitable mold. Solvent and air are supplied underthe control of selectively operable valves through pressure responsive poppet valves to the same common conduit as the chemicals for washing the chemicals from the conduit, from the outer face of the chemical poppet valves, and for further washing the mixing chamber. The controllable valves, the actuators for the controllable valves, and a drive motor for the counter rotating shafts are all contained on a main body that may be of a suitable size without restriction, and the check valves, pressure responsive valves, common conduit, counter rotating mixer shafts, and mixing chamber are all contained in a common flat head and generally symmetrically in a horizontal plane, so that the head is of minimum height for insertion into a mold. The chemical, solvent and air passage ways, and the mechanical drive between the mixer and drive motor all have separable couplings between the head and main body, so that an extension may be selectively inserted so that the automatic valve and mixing head may be inserted deeply into a mold cavity, for example to insert foam into a mold cavity approximately 1 inch high, of indefinite length, and of a width of 3 to 4 feet for making rigid foam panels with outer facing materials of metal or the like.

BACKGROUND OF THE INVENTION

In recent years, rigid foam panelling has been used increasingly in thebuilding trade, and various machines for forming the panelling andmixing the foaming chemicals are known. When depositing foam in an opentop trough or mold, no particular difficulties arise with respect to thesize of the mixing and depositing unit. However, when rigid outer skinsare to be assembled with the foam as a core, there are considerableproblems in the prior art.

When the rigid outer skins are assembled and substantially in theirfinal position, that is parallel to each other and spaced a smalldistance apart before the foaming chemicals are deposited between them,long thin probes have been used to conduct the mixed chemicals into thespace between the outer skins and deposit the chemicals. Such a probe isrequired to be as long as the panels are wide, which may be 3 to 6 feet,for example. It is desirable to have the chemicals foam as quickly aspossible after the assembly moves into the curing and pressure tunnel ofa conventional system, but quickly foaming chemicals present numerousproblems in a long probe. Further, there is the difficulty of cleaningsuch a long probe.

It has been known to connect panels together at their edges oppositefrom the foam depositing means and pivot them apart a relatively greatdistance to insert the conventional bulky foam mixing units into thethus formed space, but this is very difficult with rigid outer skins,such as ribbed sheet steel, and in fact impossible when the sheet steelis provided in continuous strips, from for example a rolling mill,without having an excessive distance between the foam depositing stationand the pressure tunnel to allow the sheet steel to be twisted to aparallel condition; such a long transition run would require that thefoam chemicals have considerable delay in their foaming, which would inturn undesirably greatly lengthen the curing tunnel.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide apparatus for mixingfoamable chemicals and depositing them in a mold with a minimum travelof the mixed chemicals within the apparatus, and further to provide themixing portion of the apparatus of sufficiently small dimensions in onedirection that it may be inserted into a narrow mold gap.

A main body is provided to remain outside of the mold cavity and housethe bulky item such as the mixer driving motor, controllable valves forthe chemicals and an air-solvent mixture for cleaning, actuators for thecontrollable valves, interal piping and calibration mechanisms incombination with a minimum height head that may be inserted entirelyinto the narrow mold cavity, which head includes counter rotating mixershafts, check valves for the foam chemicals, pressure operated poppetvalves for the separately provided chemicals and solvent-air mixture,and a common conduit wherein the chemicals first contact each other andwherein the poppet valves open so that solvent-air mixture will flushacross the faces of the chemical poppet valves in cleaning the conduit,counter rotating shafts and mixing chamber.

In the main body, solenoid valves are provided to control the supply ofsolvent, air, and catalyst or the like. The main foamable chemicals arepreferably provided in a recirculation circuit to be selectivelyfurnished to the pressure responsive poppet valves and check valves bythe simultaneous shifting with a single actuator of two pivoted ballvalves of unique construction.

The head and main body have complimentary couplings for the mixer drivershaft and conduits carrying the chemicals, solvent and air, so that theymay be directly connected or connected by means of a selectivelyinserted extension having correspondingly identical couplings. Anextension may be selected according to the width of the molding zone tobe covered.

BRIEF DESCRIPTION OF THE DRAWING

Further objects, features and advantages of the present invention willbecome more clear from the following detailed description of thedrawing, wherein:

FIG. 1 is a top plan view of the apparatus for supplying, mixing anddepositing foamable chemicals according to the present invention;

FIG. 2 is a side elevation view of the apparatus of FIG. 1;

FIG. 3 is a cross-sectional view taken along line III--III of FIG. 2;

FIG. 4 is a perspective view of the coupling provided between the mixershafts, and the head driving shafts, and further for the same couplingprovided between the main head drive shaft and body drive shaft;

FIG. 5 is a cross-sectional view taken along line V--V of FIG. 1;

FIG. 6 is a cross-sectional view taken along line VI--VI of FIG. 1;

FIG. 7 is a top plan view, with portions broken away, of an extension tobe selectively inserted between the head and main body of FIG. 1; and

FIG. 8 is an end view of the extension shown in FIG. 7.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

As shown in FIGS. 1 and 2, the apparatus generally comprises a main bodyto the left of line 10, which includes couplings to supply for (notshown) compressed air, solvent, first and second foamable chemicals, anda third chemical to be added to the mixture, for example as a catalyst;controllable valves and their controls for selectively supplying theair, solvent, and chemicals to a plurality of respective couplingsgenerally along line 10; a drive motor and drive shaft for a mechanicalmixer, with the drive shaft terminating in a coupling generally at line10. To the right of line 10, there is provided a live mixing head ofminimum height that may be inserted into a mold cavity, and whichcontains check valves for the chemicals, pressure responsive poppetvalves for the air, solvent and chemicals, a mixing chamber havingcounter rotating mechanical mixers, and a discharge port; the headfurther contains complimentary couplings along line 10 for thechemicals, air, solvent and drive shaft. The extension of FIGS. 7 and 8may be inserted at line 10 between the head and main body.

The fluid contacting portions of the MAIN BODY are preferably formed bydrilling passages in rigid blocks and rigidly connecting tubes and thelike in such passages, so that the blocks may be rigidly assembledtogether by clamping or welding to form all internal passages for fluidmaterials being handled. The following pipe couplings are providedleading into the main body, which may be of any conventionalconstruction, for example threaded apertures for receiving the threadedends of flexible fluid pressure lines (not shown); coupling 11 receivesa chemical such as a catalyst or additive; coupling 12 receives one ofthe foamable chemicals under pressure; coupling 13 returns the firstfoamable chemical to its source where it may be pressurized andrecirculated to coupling 12; coupling 14 discharges the second foamablechemical so that it may return to its source to be pressurized andreturned to coupling 15; coupling 15 receives the pressurized secondfoamable chemical; coupling 16 receives air under pressure; coupling 17receives solvent under pressure. The source of the pressurized air,solvent, and three chemicals is not shown, because it is conventional.

In traveling along internal passage way 18, the third chemical fromcoupling 11 is controlled by a solenoid operated valve 19, which iselectrically actuated between a first position closing passage way 18and a second position opening passage way. A conventional needle valve20 may be threaded into and out of the passage way 18 to correspondinglycalibrate the flow of the third chemical through the passage way 18 whenthe valve 19 is opened. Cross passage way 21 is in fluid communicationwith passage way 18. Needle valve 22 may be closed when it is desired tocalibrate the flow of the third chemical by opening plug 23 so thatpassage way 21 may be connected to a suitable meter, while needle valve20 is adjusted. After adjustment, plug 23 is replaced afterdisconnecting the meter and valve 22 is either fully opened if the thirdchemical is desired or fully closed if the third chemical is notdesired. Since the third chemical is usually an additive or a catalyst,such calibration is important due to its critical nature. Passage way 21is further fluid connected to passage way 23, which terminates at thecoupling line 10.

The main body is provided with a large vertically extending bore 24having at its opposite ends counter bores of larger diameter 25, whichbore 24 at its center forms a valve chamber into which passage way 26discharges the first foamable chemical received from coupling 12.Passage way 27 returns the first foamable chemical from the valvechamber to fluid coupling 13 so that the first chemical may travel in aclosed recirculation path between the valve chamber and supply when theapparatus is not in active use. Plugs 28 and 29 have first cylindricalportions substantially the same diameter as and telescopically receivedwithin the bore 24, and second cylindrical flange portions receivedwithin the counter bores 25. O-rings are provided to seal the plugs, asshown, in the bore 24 to correspondingly seal the valve chamber; twotension bolts 30 tightly hold the plugs in place as shown. A singleshaft 31 extends completely through the top plug 29, with an O-ring sealas shown, and into a blind bearing bore in the plug 28. Within the valvechamber, the shaft 31 has rigidly attached, parallel and horizontallyextending arms mounting with universal lost motion at their outer ends aball movable valve member 32. Preferably, the ball member is made from aresilient, synthetic resin that is highly resistant to the chemicalaction and other environmental conditions associated with the foamablechemicals. A passage way 33 extends from within the valve chamber to thecoupling line 10. The passage ways 27 and 33 respectively form opposedannular valve seats within the valve chamber closely adjacent to theball 32, so that with a 10° to 15° total pivotal movement of the shaft31, the ball 32 may be pivoted between a position sealing passage way27, its illustrated neutral position, and a position sealing passage way33. In either of its sealed positions, the valve chamber will bepressurized by the first chemical from passage way 26 freely enteringthe valve chamber, so that the ball 32 will be tightly pressed by suchpressure into further contact with the stationary annular valve seatformed by the respective passage way 27 or 33, which movement isaccommodated by the universal lost motion connection between the ball 32and parallel arms rigidly connected to shaft 31. When the valve is inposition sealing the return passage way 27, the first chemical enterscoupling 12, passes through passage way 26, the valve chamber, andpassage way 33 to the coupling line 10.

A detailed view of the above-described valve is shown in FIG. 6, withthe previously mentioned parallel arms being shown at 34 and 35, whereinat one end they are rigidly secured, for example by welding, to theshaft 31, and where at their outer free ends, they have alignedoversized apertures 36 respectively receiving therein pins ofconsiderably smaller diameter 37, which pins 37 are rigidly secured toand support ball 32. After the shaft and plugs are assembled, a crosspin 38 is threadably secured in a block 39 that is fixed to the upperplug 29, which pin 38 is received within an annular groove 40 on theshaft 31, to prevent axial movement of the shaft 31 and at the same timeallow the pivotal valving movement of the shaft 31. A control arm 41 hasone end fixedly secured to the upper end of the shaft 31, and itsopposite end secured with lost motion to a reciprocating actuator fork42 by means of a vertically extending pin 43 and aligned oversizedapertures in the fork members 42 in the adjacent portion of arm 41.

The internal passage ways and valve for the second chemical with supplyand return couplings 15, 14 respectively, is a mirror image of thatalready described with respect to the first chemical, so that furtherdescription of control of the second chemical is unnecessary.Reciprocation of actuator member 42 will thus simultaneously operate thevalve for the first chemical and the valve for the second chemical in anidentical manner.

Actuator member 42 is reciprocated by piston rod 44, which is threadedinto the actuator member 42 and locked in adjusted position by lock nut45. A conventional type of fluid cylinder, single acting with springreturn, 46 is provided to reciprocate piston rod 44 as controlled bysolenoid actuated valve 47 that controls the supply and exhaust of fluidto the cylinder 46 from control fluid coupling 48 that would lead to aconventional source of control fluid (not shown).

Pressurized air supplied to coupling 16 moves through passage way 49under the control of selectively opened or closed solenoid actuatorvalve 50 through calibrating needle valve 51, cross passage 52 to bothbranch passages 53, 54 terminating at the coupling line 10. In a similarmanner, pressurized solvent supplied to coupling 17 passes throughpassage way 54, selectively opened or closed solenoid actuator valve 55,calibrating needle valve 56, common cross passage way 52, and bothbranch passage ways 53, 54 to the couplling line 10.

For driving the mixer, the later be described, the motor and shaftarrangement are provided on the main body. Preferably, the motor 57 ishydraulically driven by motive fluid supply and exhaust ports 58, 59under suitable valving control (not shown). Drive shaft 60 is rotatablymounted by bearings (not shown) in the main body, to be drivinglyconnected at one end to the rotary output of the motor 57 and have itsopposite end terminate in a suitable coupling to be later desribed withrespect to FIG. 4 at the coupling line 10.

The MIXING HEAD will now be described as illustrated in FIGS. 1, 2, 3and 5. The mixing head is shown in FIGS. 1 and 2 to the right ofcoupling line 10 and includes the following separable items: checkvalves and gear block 60, automatic pressure responsive valve block 61,common conduit and mixing chamber block 62, bearing block 63, and fanspray nozzle 64. Suitable threaded fasteners are provided to releasablysecure these basic elements together to form a rigid head structure,which elements are separated for periodic repair and cleaning.

Unit 60 has parallel and substantially identical straight throughpassage ways 65 aligned with and in fluid communicating with branchpassage ways 53, 54 respectively; spring biased check valves 66respectively for the first and second chemical passage ways 33; acounter rotating gear pair 67 having one of the counter rotatingintermeshed spur gears of pair 67 being mounted on a shaft coupled todrive shaft 60. Only one each of the common elements are shown.

Block 61 is provided with through passage ways respectively fluidcommunicating with and aligned with passage ways 65 and check valves 66,and each containing within block 61 pressure responsive poppet valves.Each pressure responsive poppet valve includes a valve head 68, spring69 that determines the pressure at which the poppet valve will open, andspring plate 70 threadably secured for axial adjustment on the valvestem connected to the valve head 68, to determine the spring pressureand thus the pressure at which the valve will open. Since all of thesepoppet valves are substantially identical, they will not be separatelyshown or separately described. These poppet valves may be ofconventional construction per se, as may the check valves. As is seen inFIGS. 5 and 1, each of the poppet valve heads 68 extend into a commonconduit 71. In FIG. 5, the outermost right and left hand valve heads 68control the flow of mixed pressurized air and solvent into the commonconduit 71 from the branch passage ways 53, 54. The left hand inner head68 controls the flow of the second chemical into the common conduit,while the right hand inner head 68 controls the flow of the firstchemical into the inner conduit. Preferably, the third chemical providedin lines 21, 23 will be mixed with the first chemical in the passage way33 so that it will also be controlled by the right hand innermost poppetvalve head 68. It is noted that the poppet valves for the first andsecond chemicals are substantially larger than the poppet valves for theair and solvent. The common conduit 71 is primarily formed by a recessin the left hand face of the unit 62.

The unit 62 is generally hollow to provide a mixing chamber opening influid communication into the common conduit 71 at one end and in fluidcommunication with the dipensing nozzle 64 at its opposite end. Thedispensing nozzle 64 may be of conventional construction to provide afan-shaped discharge of the chemicals; alternatively, the nozzle 64 maybe plugged and a rectangular opening may be provided in the bottom ofthe unit 63 to provide a downward discharge 72 of the mixed chemicals,with it being understood that the rectangular passage way at the bottomof 63 would be plugged when the nozzle 64 would be in operation. Thus,the chemicals may be dispensed in any desired patterns, including theplugging of the rectangular opening and the removal of the nozzle 64 sothat the chemicals would merely discharge from the right hand most endof the unit 63.

Within the mixing chamber 73, as shown in FIGS. 1 and 3, there arerotatably mounted parallel shafts 74, 75. Axially along each of theshafts 74, 75, there are through diametric bores at even spacing, whichbores are formed at right angles with respect to their adjacent bores.Roll pins are inserted through each of the bores, respectively, withsuch roll pins being formed of sheet metal bent into a tube with alongitudinal gap and of a greater relaxed diameter than the bores, sothat they may be compressed and inserted into the bores and held inplace by friction. The shafts 74, 75 with their cross bores and rollpins 76 are constructed in an identical manner. The opposite ends of theshaft 74 are rotatably mounted in suitable bearings, with sealsprotecting the bearings, in the walls of the unit 62. Short drive shaftsrespectively couple the shafts 74, 75 with respective ones of the gearsof gear pair 67, so that the shafts 74, 75 are counter rotated inunison. Although the shafts 74, 75 are identical in construction, theyare rotated 90° with respect to each other so that adjacent roll pins 76of the two shafts will be offset to avoid interference and to facilitatemixing of the chemicals when the shafts rotate. Pins 76 extend from theshaft a distance greater than one-half the distance between shafts toprovide shear mixing as distinguished from impingement mixing.

Since all of the above mentioned shafts are drivingly interconconnectedand since the main body is separable from the units 60, 61, 62, whichunits are in turn separable from each other, drive shaft couplings areprovided at each separation as shown in FIG. 4. Since each of thesedrive shaft couplings is identical, only one will be described indetail. Shaft "A" is provided with a cross bore and roll pin 77 that isrotationally drivingly received within opposite slots (only one beingshown) 78 in a cup-shaped member 79, which cup-shaped member isdrivingly and fixedly secured to shaft "B." Due to the pin and slotconnection, the cup-shaped member 79 and pin 77 may be axiallyseparated, to correspondingly axially separate the shafts "A" and "B."One member to be separated would carry shaft "B" and rotationallysupported with sleeve bearing 80 and fluid seal 81; the other shaft "A"would be within the other member to be separated, but would not need abearing since its outer diameter is substantially the same as the innerdiameter of the cup-shaped member 79(clearance exagerated).

In assembling or disassembling for repair or cleaning purposes, theunits 60, 61 are fixedly secured to the main body by means of aplurality of bolts 82 extending through units 60, 61 and threadablysecured to the main body. The unit 62 is in turn secured to the unit 61by means of bolts 83 extending through bores 84 in unit 62 andthreadably into unit 61.

OPERATION OF THE APPARATUS OF FIGS. 1-6

When foamable chemicals are not being mixed and dispensed, solenoidactuator valves 19, 50 and 55 are closed to prevent passage of the thirdchemical, compressed air and pressurized solvent to the mixing chamber.Further, solenoid actuator valve 47 is in a position such that thepiston rod 44 will be moved to the right as shown in FIG. 1 and FIG. 2to engage the balls 32 in the annular valve seats of passages 33 so thatthe first and second chemicals will enter port 12, circulate through thevalve chamber and press the balls 32 tightly into sealing engagementwith passage ways 33, and the exit through port 13 (respectively ports15 and 14 for the second chemical), so that the first and secondchemicals will travel in a closed recirculation loop between the valvechamber and the source without passing to the mixing chamber. Thisrecirculation is very important in providing the proper flow of chemicalunder controlled pressure as closely as possible to the mixing chamberbefore dispensing so that the temperatures of the chemicals may beaccurately controlled, so that the pressure may be accuratelycontrolled, and so that when the chemical valves are opened, the rightproportion of the two chemicals may be mixed. The proportion of themixture, the temperature and the like is critical in determining thefoam reaction time, which in turn is critical in accurately constructingthe length of the conveyor run prior to reaching the pressurized tunneland the length of the pressurized tunnel wherein the foamed materialsare cured.

When it is desired to mix and dispense the chemicals, solenoid operatedvalve 47 is changed so as to move the piston rod 44 and actuator member42 to their extreme left hand position, as shown in FIGS. 1 and 2, sothat valve ball 32 will be moved to the position to close returnconduits 27, so that the first chemical supplied to coupling port 12 andthe second chemical supplied to coupling port 15 and circulating withinthe valve chamber will immediately pass through respective passage ways33 to the mixing chamber 73. Since the valve ball 32 moves from oneclosed position through its neutral illustrated position to its oppositeclosed position, the flow of chemicals within passage ways 26 will besubstantially uneffected to provide for a smooth transition from returnpassage way 27 to supply passage ways 33. Also, the motive fluid will besupplied to the motor 57 to rotate the counter rotating mixer shafts 74,75. When pressurized first and second chemicals are provided in passageways 33, they automatically open up check valves 66 and poppet valves68, so that the first and second chemicals are separately delivered tocommon conduit 71 through poppet valve head 68, from where they travelto mixing chamber 73 where they are mixed by the rotating pins 76 priorto being dispensed through nozzle 64 or being dispensed downwardly inflow 72.

When dispensing is terminated, suitable controls (not shown) willautomatically actuate solenoid operator valve 47 to move valve balls 32from their far left hand position, as viewed in FIGS. 1 and 2, to theirfar right hand position to prevent further flow of chemicals 1 and 2 tothe mixing chamber, and substantially simultaneously solenoid operatedvalves 50, 55 will be opened to permit flow of mixed compressed air andsolvent through branch passage ways 53, 54 and their respective pressureoperated poppet valves into common conduit 71. Of course, when thepoppet valves for the solvent and air are opened, the poppet valves forthe first and second chemicals will be closed due to the lack ofchemical pressure in passage ways 33 when ball valves 32 are shifted totheir right hand position closing off passage ways 33. As shown in FIG.5, the mixture of solvent and air will be supplied into common conduit71 from the outermost poppet valve heads 68 to sweep across the nowclosed innermost poppet valve heads 68 control the two chemicals),around shafts 74, 75 and into the mixing chamber 73. During the supplyof solvent and air, rotation of the shafts 74, 75 is continued so thatthey will be thoroughly cleaned.

Thereafter, the solenoid operated valves 50, 55 are closed and rotationof the shafts 74, 75 may or may no be discontinued. When it is desiredto dispense more foam, the above process is repeated.

If it is desired to provide a catalyst or other third chemical fromcoupling port 11, the solenoid operated valve 19, is opened at the sametime that passage ways 33 are opened by shifting of the ball valve 32towards the left in FIGS. 1 and 2, and the third chemical is then movedinto first chemical passage way 33.

THE EXTENSION OF FIGS. 7 AND 8

When it is desired to dispense foam across a considerable width within amolding chamber, the unit 60 is separated from the main body alongcoupling line 10 and the extension of FIGS. 7 and 8 is inserted betweenunit 60 and the main body. Accordingly, the extension of FIGS. 7 and 8may be of any desired length. For example, the extension of FIGS. 7 and8 may be 3 feet long so that with the mixing head to the right ofcoupling 10 in FIGS. 1 and 2, the entire extension and mixing head unitwould be 4 feet long so that the mixing head could be inserted into a 4foot wide panel molding cavity and reciprocated generally with a 4 footamplitude to lay down a zigzag pattern of foam within the molding cavitythat would be moving continuously at right angles to the reciprocationof the mixing head.

It is noted from FIGS. 1, 2, 3 and 5 that the mixing head has a verysmall height, which is its critical dimension with respect to enteringthe molding cavity. This small height is possible because thecontrollable valves and drive motors are all connected to the main bodyand do not enter into the mold cavity, and further because the driveshafts 74, 75, the four pressure responsive poppet valves 68-70, the twocheck valves 66, the gear pair 67, and passages 65 all lie generallywithin a common horizontal plane. Due to this small height, the entiremixing head may be inserted into the mold cavity so that the twochemicals will not contact each other until the last minute andthereafter be immediately mixed and discharged with a minimum of timewithin the mixing head after being combined. This minimum time withinthe mixing head is accomplished by the pressure responsive valves beinglocated as closely as possible to the mixing chamber, which pressureresponsive poppet valves will prevent mixing of the chemicals prior totheir entering the common conduit 71. Further, this provides for aminimum surface area to be cleaned by the solvent and air.

The extension shown in FIGS. 7 and 8 includes a plate 100 having aplurality of bolt holes 101, through which bolts (not shown) may passand be threaded into the main body. Further, the extension includes agenerally rectangular cross section block 102, of any desired length,having its left hand end, as viewed in FIG. 7, sealingly and rigidlysecured, for example welding, to the plate 100, and interbraced withrespect to the plate 100 by buttresses 103. Four longitudinallyextending bores 104 extend for the entire length of the extension andparallel to each other in alignment with and in the same pattern as thebores 84 shown for the mixing head in FIG. 5, so that tension boltssimilar to, but considerably longer than bolts 82 may be passed throughunits 62, 61, 60, block 102 and plate 101, in order and screwed into thethreaded blind passage ways in the main body to secure the mixing headon the right hand end of the extension and to further brace theextension with respect to the main body.

The extension further carries a single drive shaft 105 rotatablysupported in sleeve bearings 106, 107 and having a coupling at one endsimilar to coupling 77 and a coupling at its opposite end similar tocoupling 78, 79. This drive shaft would be used to transmit the mixerdriving power from the main body to the mixing head.

Further, the extension is provided with drilled passage ways 108, 109,110 and 111 that when assembled would be in communication at their lefthand end with respectively passage ways 53, 33, 33 and 54 forrespectively passing air-solvent mixture, the first chemical, the secondchemical, and air-solvent mixture. The right hand end of bores 108, 109,110, 111, when assembled, would be respectively fluid connected toair-solvent passage way 65, first chemical check valve 66, secondchemical check valve 66, and air solvent passage way 65 in the mixinghead.

Any type of releasable fluid couplings may be provided between themixing head and main body along coupling line 10, for example abuttingpassage ways with an O-ring between, but the fluid passage way couplingmeans for the main body would be substantially identical to those forthe right hand portion of the extension shown in FIG. 7 and the couplingmeans for the mixing head would be substantially identical to thecoupling means for the left hand portion of the extension as shown inFIG. 7, so that the mixing head may be either directly coupled to themain body or coupled to the main body with the interposition of theextension of FIG. 7, without any modification except for the provisionof longer bolts 82. Further, that portion of the drive coupling in FIG.4 that would be provided for the mixing head would be substantiallyidentical to that provided for the left hand end of the drive shaft 105,and the other portion of the coupling of FIG. 4 for the main body wouldbe substantially identical to that provided for the right hand end ofshaft 105. Where the shafts 74, 75 enter from the mixing chamber intothe unit 61, suitable rotational seals are provided so that chemicalsmay not be in contact with the gear pair 67, the shaft 105, or variousbearings.

It is thus seen that the apparatus of the present invention provides fora universally adapted foam mixing unit that may dispense foam in a fanshape, downwardly or outwardly, inmost any type of mold, including anopen top mold and a mold having a very narrow elongated opening, forexample of only 1 inch height between opposed rigid panels partiallyshown in FIG. 2. As one specific example of use, the apparatus shown inthe drawing may be used as the mixing and dispensing apparatus ofcopending application Ser. No. 570,451, now Pat. No. 4,051,209, filledon the same date with the present application, and commonly assigned.The opposed rigid panels or sheets would define therebetween a moldcavity into which the head and extension are fully insertable due totheir small height with the main body always remaining outside of themold cavity.

While a specific preferred embodiment of the present invention has beenshown and described in detail, with particular and specific advantagesbeing attributable to such details, variations, modifications andfurther embodiments are contemplated according to the broader aspects ofthe present invention, all as defined by the spirit and scope of thefollowing claims.

I claim:
 1. An apparatus for mixing at least two foamable fluentchemicals and depositing the chemicals in a mold cavity, the improvementcomprising: controllable valve means for selectively supplying and notsupplying separately the two chemicals; two automatic valve meansnormally biased closed and opened at a predetermined fluid pressure ontheir inlet side for passing fluids to their outlet side; conduit meansfluid connected between each of said controllable valve means and aseparate one of said automatic valve means for separately conducting thetwo chemicals supplied by said controllable valve means to the inletsides respectively of said automatic valve means; a mixing chamber indirect fluid communication with the outlet sides of said automatic valvemeans for commonly receiving both of said chemicals passing respectivelythrough said automatic valve means; mechanically driven meansoperatively mounted within said mixing chamber for mixing said twochemicals in said mixing chamber; means operatively associated with saidmixing chamber for discharging the thus mixed chemicals from said mixingchamber to the mold cavity; motor means operatively associated with saidmechanically driven mixing means for driving said mechanically drivenmixing means; a main body carrying said motor means and saidcontrollable valve means; drive means mechanically connected to saidmain body for moving said main body toward and away from a mold cavity;a mixing head being supportively connected at one end to said main bodyand extending as a cantilevered beam freely from said main body at itsone end toward its opposite end, said mixing head carrying saiddischarge means adjacent its opposite end, and further carrying saidmixing chamber, said mechanically driven means and said automatic valvemeans.
 2. The apparatus of claim 1, wherein said mechanically drivenmixing means includes two parallel shafts respectively rotatably mountedin said mixing chamber and extending generally in a common plane withsaid automatic valve means, and further having a plurality of radiallyextending fluid beaters drivingly connected to said shafts; each of saidshafts having a beater end in said mixing chamber, and a drive endoutside of said mixing chamber and sealed with respect to said mixingchamber; gear means drivingly interengaged and respectively drivinglyconnected to said shafts for synchronously counter rotating said shaftsoutside of said mixing chamber.
 3. The apparatus of claim 1, furtherimcluding: a separate extension member being releasably and selectivelysecured to said apparatus and having therein a rotatably mounted driveshaft with releasable coupling means at its opposite ends for beingreleasably connected to said mechanically driven mixing means at one endand to said motor means at its opposite end; a plurality of conduitswithin said extension member for respectively carrying the twochemicals, with each having releasable coupling means at opposite endsfor respectively connecting to said controllable valve means and saidautomatic valves; coupling means operatively associated with saidcontrollable valve means for directly connecting said controllable valvemeans with their respective automatic valve means independently of saidextension member; and said extension having a length that is a multipleof the length of said mixing chamber.
 4. The apparatus of claim 3,wherein said main body has an outer coupling portion with exposed portsrespectively fluid connected to the outlet side of said controllablevalve means and a releasable mechanical coupling for said drive motormeans in a fixed predetermined pattern; said mixing head having anexposed portion remote from said discharge means having exposed portsrespectively fluid connected to said automatic valve means andreleasable mechanical coupling means for said mechanically driven mixingmeans in a fixed pattern complimentary to the pattern of said main bodyso as to be respectively sealingly and drivingly interengaged; andreleasable means operatively associated with said main body for rigidlyholding said head and main body in said interengaged position.
 5. Theapparatus of claim 4, wherein said mixing head and extension member eachhave a width several times their height, and a length several timestheir width, respectively.
 6. The apparatus of claim 4, furtherincluding check valve means in said mixing head fluid connected betweeneach of said chemical automatic valve means and said chemicalcontrollable valve means.
 7. The apparatus of claim 1, includingautomatic valve means immediately adjacent at least one of said firstmentioned two chemical automatic valve means and having a solvent inletand a solvent outlet for passing solvent from its inlet to its outletonly at a pressure above a predetermined pressure; controllable valvemeans for selectively supplying solvent under pressure to the inlet ofsaid solvent automatic valve means; conduit means serially fluidconnecting the outlet of said solvent automatic valve means, the outletof said at least one chemical automatic valve means and said mixingchamber, in order, so that solvent passing through the outlet of saidsolvent automatic valve means will flow past and wash the outlet sidevalve face of said at least one chemical automatic valve means beforepassing into said mixing chamber.
 8. The apparatus of claim 7, whereinsaid mechanically driven mixing means includes two parallel shaftsextending generally in a common plane with said automatic valve means,and further having a plurality of radially extending fluid beatersdrivingly connected to said shafts; each of said shafts having a beaterend in said mixing chamber; gear means drivingly interengaged andrespectively drivingly connected to said shafts for synchronouslycounter rotating said shafts outside of said mixing chamber.
 9. Theapparatus of claim 7, further including: a separate extension memberbeing releasable and selectively secured to said apparatus and havingtherein a rotatable mounted drive shaft with releasable coupling meansat its opposite ends for being releasable connected to said mechanicallydriven mixing means at one end and to said motor means at its oppositeend; a plurality of conduits within said extension member forrespectively carrying the two chemicals and solvent, with each havingreleasable coupling means at opposite ends for respectively connectingto said controllable valve means and said automatic valves; couplingmeans operatively associated with said controllable valve means fordirectly connecting said controllable valve means with their respectiveautomatic valve means independently of said extension member; and saidextension having a length that is a multiple of the length of saidmixing chamber.
 10. The apparatus of claim 9, wherein said main body hasan outer coupling portion with exposed ports respectively fluidconnected to the outlet side of said controllable valve means and areleasable mechanical coupling for said drive motor means in a fixedpredetermined pattern; said mixing head having an exposed portion remotefrom said discharge means having exposed ports respectively fluidconnected to said automatic valve means and releasable mechanicalcoupling means for said mechanically driven mixing means in a fixedpattern complimentary to the pattern of said main body so as to berespectively sealingly and drivingly interengaged; and releasable meansoperatively associated with said main body for rigidly holding said headand main body in said interengaged position.
 11. The apparatus of claim7, including a second solvent automatic valve means substantiallyidentical to said first mentioned solvent automatic valve means andhaving its inlet side commonly fluid connected with the inlet of saidfirst mentioned solvent automatic valve means and its outlet sideimmediately adjacent the other of said chemical automatic valve means;said four automatic valve means being arranged substantially in a commonplane with said chemical automatic valve means to the interior and saidsolvent automatic valve means to the exterior; said conduit meansfurther conducting the solvent for the outlet side of said secondsolvent automatic valve means across the outlet side face of said secondchemical automatic valve means and then to said mixing chamber forwashing said second chemical automatic valve means; said conduit meansopening into one end of said mixing chamber and said discharge meansopening into the opposite end of said mixing chamber so that the solventafter washing said chemical automatic valve means will pass through theentire interior of said mixing chamber before being discharged throughsaid discharge means.
 12. The apparatus of claim 11, including at leastone drive shaft generally lying in said common plane and being drivinglyconnected to said mechanically driven mixing means, said shaft extendingthrough said conduit means between said chemical automatic valve means,and having rotational seal means in the wall of said conduit means sothat the portion of said shaft exposed to the chemicals will be washedby the solvent passing through said conduit means into said mixingchamber.
 13. The apparatus of claim 12, wherein said mechanically drivenmixing means includes two parallel shafts respectively rotatably mountedin said mixing chamber and extending generally in a common plane withsaid automatic valve means, and further having a plurality of radiallyextending fluid beaters drivingly connected to said shafts; each of saidshafts having a beater end in said mixing chamber, and a drive endoutside of said mixing chamber and sealed with respect to said mixingchamber; gear means drivingly interengaged and respectively drivinglyconnected to said shafts for synchronously counter rotating said shaftsoutside of said mixing chamber.
 14. The apparatus of claim 12, furtherincluding: a separate extension member being releasably and selectivelysecured to said apparatus and having therein a rotatably mounted driveshaft with releasable coupling means at its opposite ends for beingreleasably connected to said mechanically driven mixing means at one endand to said motor means at its opposite end; a plurality of conduitswithin said extension member for respectively carrying the two chemicalsand solvent, with each having releasable coupling means at opposite endsfor respectively connecting to said controllable valve means operativelyassociated with said controllable valve means and said automatic valves;coupling means for directly connecting said controllable valve meanswith their respective automatic valve means independently of saidextension member; and said extension having a length that is a multipleof the length of said mixing chamber.
 15. The apparatus of claim 14,wherein said main body has an outer coupling portion with exposed portsrespectively fluid connected to the outlet side of said controllablevalve means and a releasable mechanical coupling for said drive motormeans in a fixed predetermined pattern; said mixing head having anexposed portion remote from said discharge means having exposed portsrespectively fluid connected to said automatic valve means andreleasable mechanical coupling means for said mechanically driven mixingmeans in a fixed pattern complimentary to the pattern of said main bodyso as to be respectively sealingly and drivingly interengaged; andreleasable means operatively associated with said main body for rigidlyholding said head and main body in said interengaged position.
 16. Theapparatus of claim 15, wherein said patterns have said ports andreleasable couplings in a common plane.
 17. The apparatus of claim 15,wherein said extension member coupling means at one end aresubstantially identical to and in the same pattern as said main bodyports and coupling, and at its opposite end in substantially the samepattern and substantially identical to said mixing head ports andcoupling so as to be sealingly and drivingly connected between saidmixing head and main body for conducting fluid and mechanical drivingpower from said main body to said mixing head over a desired extendedlength; and releasable fastening means operatively associated with saidmain body for rigidly and sealingly clamping said head, extension memberand main body serially together.
 18. The apparatus of claim 2, furtherincluding: a separate extension member being releasably and selectivelysecured to said apparatus and having therein a rotatably mounted driveshaft with releasable coupling means at its opposite ends for beingreleasably connected to said mechanically driven mixing means at one endand to said motor means at its opposite end; a plurality of conduitswithin said extension member for respectively carrying the two chemicalsand solvent, with each having releasable coupling means at opposite endsfor respectively connecting to said controllable valve means and saidautomatic valves; coupling means operatively associated with saidcontrollable valve means for directly connecting said controllable valvemeans with their respective automatic valve means independently of saidextension member; said extension having a length that is a multiple ofthe length of said mixing chamber; said main body having an outercoupling portion with exposed ports respectively fluid connected to theoutlet side of said controllable valve means and a releasable mechanicalcoupling for said drive motor means in a fixed predetermined pattern;said mixing head having an exposed portion remote from said dischargemeans having exposed ports respectively fluid connected to saidautomatic valve means and releasable mechanical coupling means for saidmechanically driven mixing means in a fixed pattern complimentary to thepattern of said main body so as to be respectively sealingly anddrivingly interengaged; and releasable means operatively associated withsaid main body for rigidly holding said head and main body in saidinterengaged position.
 19. The apparatus of claim 18, wherein saidextension member coupling means at one end are substantially identicalto and in the same pattern as said main body ports and coupling, and atits opposite end in substantially the same pattern and substantiallyidentical to said mixing head ports and coupling so as to be sealinglyand drivingly connected between said mixing head and main body forconducting fluid and mechanical driving power from said main body tosaid mixing head over a desired extended length; and releasablefastening means operatively associated with said main body for rigidlyand sealingly clamping said head, extension member and main bodyserially together.
 20. The apparatus of claim 2, wherein each of saidshafts has a serial array of through diametric bores along its lengthwhich bores are angularly oriented with respect to the adjacent bores,said beaters are pin means rigidly secured in each of said bores andhaving opposite ends extending radially from said shafts; said shaftsare angularly displaced with respect to each other so that one pin ofone shaft will have a center line passing through the rotational axis ofthe other shaft and intersecting a pin of the other shaft at asubstantial angle in one position of said shafts.
 21. The apparatus ofclaim 20, wherein each of said pins is a roll pin only frictionallyconnected with its respective shaft by virtue of having a free relaxedgeneral outer diameter substantially larger than the inner diameter ofits associated bore.